(ly_module_define): only define variable if

[lilypond.git] / lily / rest-collision-engraver.cc

diff --git a/lily/rest-collision-engraver.cc b/lily/rest-collision-engraver.cc
index b5aaa7722e31360a6cd8be93fa836b2e58230c73..e63fc171b08af94602335e866a623221378163b7 100644 (file)
--- a/lily/rest-collision-engraver.cc
+++ b/lily/rest-collision-engraver.cc
@@ -3,45 +3,47 @@
 
   source file of the GNU LilyPond music typesetter
 
-  (c)  1997--2002 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+  (c) 1997--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
 */
 
 #include "warn.hh"
-#include "rest-collision.hh"
 #include "engraver.hh"
-#include "note-collision.hh"
+#include "rest-collision.hh"
 #include "note-column.hh"
 
 class Rest_collision_engraver : public Engraver
 {
   Item* rest_collision_;
-
+  int rest_count_; 
   Link_array<Grob> note_columns_;
 protected:
   virtual void acknowledge_grob (Grob_info);
   virtual void process_acknowledged_grobs ();
   virtual void stop_translation_timestep ();
 public:
-  TRANSLATOR_DECLARATIONS(Rest_collision_engraver);  
+  TRANSLATOR_DECLARATIONS (Rest_collision_engraver);  
 };
 
-
-
 Rest_collision_engraver::Rest_collision_engraver ()
 {
   rest_collision_ =0;
+  rest_count_ = 0;
 }
 
 void
 Rest_collision_engraver::process_acknowledged_grobs ()
 {
-  if (rest_collision_ || note_columns_.size () < 2)
+  if (rest_collision_
+      || note_columns_.is_empty ()
+      || !rest_count_ 
+      || (note_columns_.size () == rest_count_
+         && rest_count_  < 2))
     return;
 
-  rest_collision_ = new Item (get_property ("RestCollision"));
+  rest_collision_ = make_item ("RestCollision", SCM_EOL);
 
-  announce_grob(rest_collision_, SCM_EOL);
-  for (int i=0; i< note_columns_.size (); i++)
+  
+  for (int i=0; i < note_columns_.size (); i++)
     Rest_collision::add_column (rest_collision_,note_columns_[i]);
 }
 
@@ -49,7 +51,11 @@ void
 Rest_collision_engraver::acknowledge_grob (Grob_info i)
 {
   if (Note_column::has_interface (i.grob_))
-    note_columns_.push (i.grob_);
+    {
+      note_columns_.push (i.grob_);
+      if (Note_column::has_rests (i.grob_))
+       rest_count_ ++;
+    }
 }
 
 void
@@ -61,10 +67,13 @@ Rest_collision_engraver::stop_translation_timestep ()
       rest_collision_ = 0;
     }
   note_columns_.clear ();
+  rest_count_ = 0;
 }
-ENTER_DESCRIPTION(Rest_collision_engraver,
+
+ENTER_DESCRIPTION (Rest_collision_engraver,
 /* descr */       "Handles collisions of rests.",
 /* creats*/       "RestCollision",
-/* acks  */       "note-column-interface",
+/* accepts */     "",
+/* acks  */      "note-column-interface",
 /* reads */       "",
 /* write */       "");